Abstract

This dissertation explores three areas of philosophical interest: expressivist or non-cognitivist construals of normative discourse, normative construals of semantic discourse, and the plausibility of semantic non-factualism or irrealism. These three areas are not as unrelated as they may at first glance appear to be. In particular the work presented here demonstrates that the notions of disagreement and inconsistency play a crucial role in all three areas. ;Regarding the first area, it is argued that reflection on the nature of disagreement and inconsistency yields some deep problems for expressivist construals of normative discourse. The best current attempts to provide an expressivist construal of normative discourse---due to Blackburn and Gibbard---model what disagreement and inconsistency amount to on the expressivist account on the way in which forbidding p conflicts with permitting p. However, closer examination of what exactly constitutes disagreement and inconsistency raises doubts about whether such a move is legitimate. Regarding the second area, it is argued that the normativity of meaning is required to explain how disagreement itself is possible. Finally, regarding the last area, it is argued that the attempts of Boghossian and Wright to establish that semantic non factualism inflates into global non-factualism are not successful. The notion of disagreement is once more crucial here. In particular it is argued that getting clear on what exactly it is to disagree is the key to seeing where Wright's line of reasoning goes astray